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Old 11th Oct 2010, 07:27
  #24 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 76
Posts: 2,484
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SKS777FLYER;
but OH NO Captain, the magic computer here won't allow you to finesse the last few feet of your flight, for it knows better than you the energy state of the airplane....
No, not the energy state of the airplane....it knows the AoA.

As the report states, the aircraft was in "AlphaProt" mode from 150' to touchdown, (it would not have entered this mode below 100' as the mode is inhibited below that height). This provided maximum protection against stalling the aircraft in from a substantial height while maintaining sufficient energy to do so while using full back-stick.

From the Report:

"[B]elow 50', the alpha-protection threshold value increased from 14.5deg to 15.5deg. - p.48

"The airplane touched down....at an AoA of between 13deg and 14deg, ..." - p.48

So the aircraft was close to the stall. To your point then, how much more energy, for how long, did this aircraft have?

The question is open for debate but I'm not sure what the point would be. I agree with you that the discussion could be fine-tuned to argue possibility, - that an aircraft (B737, MD80, Embraer, Bombardier, etc) without such protection may have had very slightly more to contribute to arrest the final rate of descent, (12.5fps, essentially the high side of normal, but touchdown without the flare) but then again, maybe not, and pulling back would just have increased the rate of descent with a much higher pitch angle and far harder touchdown especially for the forward section of the fuselage. To my knowledge, no one has run such a scenario.

No one can argue with the outcome even if a finely-tuned argument may say that less fuselage damage may have provided longer flotation, etc, etc, but the outcome is what it is.

Cheers,
PJ2
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